The two sides held discussions on Monday and Tuesday in Istanbul on different ways of advancing the nuclear talks between Tehran and the five permanent members of the UN Security Council plus Germany, Abbas Araqchi said on Tuesday.

“It has been decided that consultations will be continued at two technical and political levels, if necessary, until the next round of talks between Iran and the P5+1 [are held],” Araqchi, who is also Iranian Deputy Foreign Minister for Legal and International Affairs, added.

During their two days of closed-door talks in Istanbul, Zarif and Ashton reviewed the progress of nuclear negotiations between Iran and the six countries.

Meanwhile, a separate expert-level meeting was also held between Iranian Foreign Ministry’s Director General for Political and International Affairs Hamid Baeidinejad and Stephen Clement, Ashton’s aide, in Istanbul.

The European Union also announced on Tuesday that the next round of talks between Iran and the six world powers over Tehran's nuclear energy program will be held in the Austrian capital city of Vienna from June 16 to 20.

Michael Mann, a spokesman for Ashton, also announced that Zarif and Ashton had "very long and useful discussions."
"They explored different possibilities as part of an ongoing process. The next formal round of [the six powers’] talks with Iran will be from 16-20 June in Vienna," Mann said in a statement.
Iran and the six countries -- Russia, China, France, Britain, the US, and Germany -- have been discussing ways to iron out differences and start drafting a final deal that would resolve the West’s decade-old dispute with Iran over the country’s nuclear energy program.
The two sides wrapped up the latest round of nuclear talks in Vienna on May 16.